Silicone coated fiberglass

The silastic is made of 2 or more thicknesses of texturized fiberglass cloth laminated together with a red high temperature fireproof silicone. It is offered in a smooth, red oxide or regular finish.


This material is often used in smelters for tapping operation joints and tolerates high temperatures. The silastic can be use in many applications: gasket for oven door base, supporting part for thermal treatment, general sealing gasket, tadpole, conveyor skirt, high temperature mat, protection curtain, expansion joint and more.


Technical Data

Thickness available 1/4", 3/8", 1/2", 3/4"
Color Red
Maximum temperature
Silicone -67°F to 550°F
Fiberglass 1000°F

Physical properties

Hardness Shore A (DIN 53505) 31
Density (ISO 1183-1 A) 1.09g/cm³
Elongation at break, %(DIN 53504 S 1) 620
Tensile strength (N/mm²) (DIN 53504 S 1) 7.50
Tear strenght N/mm (ASTM D624B) 23
Rebound resilience, % (DIN 53512) 61
Compression set (DIN ISO 815-B) 10 % (22h/175°C)
Flame resistance (UL 94) HB (0.5 mm)
Gas permeability (DIN 53536)
Room temperature Very high resistance
at 68°F Resistance 30 x superior to natural rubber
High temperature Resistance 400 x superior to butyl rubber (At high temperature, this silicone have similar results than other organic rubber)
High energy radiation resistance Excellent
Not affected by gamma and beta radiation
Very good resistance to microwave
Ozone and UV resistance Excellent
Strong bases resistance Good
Oxidizing acids resistance Bad

Electrical properties

Dielectric strength (1-mm-sheet) (DIN IEC 243 2) 23 kV/mm
Dielectric constant at 50 Hz (DIN VDE 0303) 2.8 εr
Dissipation factor (50 Hz) (DIN VDE 0303) 20 X 10^-4 tan δ
Volume resistivity (DIN IEC 93) 5 x 10^15 Ω cm
N.B. The information, details and values indicated are to the best of our knowledge. We recommend to conduct tests according to local conditions. The data is subject to some variations without notice.